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Claims  |
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What is claimed is:
1. A method of verifying the authenticity of an object which has a
continuously extending, recordable, magnetic region thereon with the
magnetic region including a randomly varying magnetic characteristic
unique to the object with detachability of the characteristic enhanced by
a selected, prerecorded, discontinuous electrical signal carried by the
magnetic region, the method comprising:
detecting the enhanced randomly varying characteristic within the
recordable magnetic region;
retrieving a prestored representation of that characteristic;
comparing the enhanced, detected randomly varying characteristic of the
recordable magnetic region to the retrieved prestored representation; and
indicating the results of the comparison.
2. A method as in claim 1 with the detectablity of the randomly varying
magnetic characteristic enhanced by saturation recording at least portions
of the electrical signal on the magnetic medium.
3. A method as in claim 2 including retrieving the prestored representation
from a selected location on the object.
4. A method as in claim 1 including encoding the detected randomly varying
characteristic and forming a present representation thereof.
5. A method as in claim 4 with the encoding step including selecting a
method of encoding from a group including;
parametric encoding, relative maxima encoding and phonetic encoding.
6. A method as in claim 5 including detecting enhanced random variations at
a plurality of spaced apart saturation pre-recorded locations of the
magnetic region.
7. An apparatus for verifying the authenticity of an object which carries a
continuously extending, recordable, magnetic region thereon with the
magnetic region containing a randomly varying magnetic characteristic
unique to the object, the apparatus comprising:
means for detecting peak values of the randomly varying characteristic
between first and second essentially equal reference values;
means for encoding the detected peak values of the randomly varying
characteristic;
means for retrieving a pre-stored representation of that characteristic;
and
means for comparing the detected randomly varying characteristic of the
recordable magnetic region to said retrieved pre-stored representation and
for indicating the results of the comparison.
8. An apparatus as in claim 7 with said encoding means including means for
determining relative displacement between selected maxima of the randomly
varying magnetic characteristic and means for forming a representation
based on said relative displacements.
9. An apparatus as in claim 8 wherein said retrieving means includes means
for sensing said prestored representation from a selected location on the
object.
10. An apparatus as in claim 8 wherein said retrieving means includes means
for sensing said prestored representation from a selected location remote
from the object.
11. An apparatus as in claim 8 wherein the magnetic region carries a
saturation pre-recorded discontinuous electrical signal for enhancing the
detectability of the randomly varying magnetic characteristic, said
detecting means including means for converting peak values of the enhanced
randomly varying magnetic characteristic to an electrical signal in
response to relative motion between the magnetic region and said detecting
means.
12. An apparatus as in claim 8 where the prerecorded enhancing signal was
erased from the magnetic region after said representation was formed and
stored, the apparatus including
means for restoring said enhancing electrical signal to the magnetic region
prior to detecting the randomly varying characteristic.
13. An apparatus as in claim 12 including:
means for erasing said enhancing electrical signal from the magnetic region
subsequent to detecting the randomly varying characteristic.
14. A method of making a verifiable object comprising:
providing a base portion;
providing a recordable region of magnetic material on the base portion;
saturation recording a selected, enhancing discontinuous electrical signal
onto the recordable region;
detecting the enhanced randomly varying magnetic characteristic within the
region;
encoding the detected unique representation of the magnetic characteristic
by determining relative displacements between selected maxima and using
relative displacements to form an encoded representation; and
storing the encoded representation for later reference.
15. A method as in claim 14 including providing a rigid base portion.
16. A method as in claim 14 including providing a flexible base portion.
17. A method as in claim 14 including saturation recording a time varying
digital signal.
18. A method as in claim 14 including recording a time varying analog
signal.
19. A verifiable object comprising:
a base portion; and
a recordable region of magnetic material on said base portion, said region
continuously extending for a selected distance with a detectable,
continuous, permanent, randomly varying magnetic characteristic unique to
the object and with a discontinuous verification electrical signal
saturation recorded thereon so as to enhance the detectability of said
randomly varying magnetic characteristic.
20. An object as in claim 19 with said saturation recorded verification
electrical signal being periodic.
21. An object as in claim 20 with said periodic electrical signal being
symmetrical about a reference value.
22. An object as in claim 20 with said verification electrical signal a
square wave signal.
23. An object as in claim 22 with said square wave signal recorded in a
self-clocking format.
24. An object as in claim 19 with a representation of said enhanced
randomly varying characteristic carried on said base portion and with said
representation encoded using a technique from a group including; absolute
encoding, parametric encoding, relative maxima encoding, phonetic
encoding.
25. A method of forming a representative profile of an object carrying a
recordable magnetic region onto which an electrical signal can be
recorded, the electrical signal enhances the detectability of a randomly
varying characteristic of the magnetic region, the method comprising:
providing the magnetic region;
recording the detectability enhancing signal onto the magnetic region;
detecting the randomly varying characteristic of the magnetic region at
least once;
collecting at least a first plurality of spaced apart peak values of the
detected randomly varying magnetic characteristic; and
encoding the characteristic by forming a sequence the members of which
define the relative displacement between selected peak values of the first
plurality.
26. A method as in claim 25 with the encoding sequence formed as a
plurality of digitized representations of the relative displacements.
27. A method as in claim 22 including collecting a second plurality of
spaced apart peak values.
28. A method as in claim 27 wherein the first polarity of peak values is
encoded by forming a first sequence, the members of which define the
relative displacement between selected peak values of the first plurality,
and wherein the second polarity of peak values is encoded by forming a
second sequence, the members of which define the relative displacement
between selected peak values of the second plurality.
29. A method as in claim 25 with at least some of the members of the
sequence representing relative displacement between first and second
adjacent peak values.
30. A method as in claim 28 with selected members of the first sequence
each representing relative displacement between first and second adjacent
peak values and with selected members of the sequence each representing
relative displacement between first and second adjacent peak values from
the second polarity of peak values.
31. An authenticatable object comprising:
a base;
an elongated, recordable magnetic region carried by said base said magnetic
region having a unique, detectable magnetic characteristic;
a time-varying, discontinuous, digital magnetic characteristic enhancing
signal recorded on said magnetic region; and
a machine readable encoded representation of said magnetic characteristic
carried by said base with said encoding based on relative displacement
between selected of said recorded discontinuities of said enhancing
signal.
32. An authenticable object as in claim 31 with said enhancing signal
saturation recorded on said magnetic region.
33. An authenticatable object as in claim 31 with said enhancing signal
having at least first and second different amplitude values with a said
discontinuity present between each said first and second amplitude value.
34. An authenticatable object as in claim 31 with said enhancing signal
formed substantially as a square wave.
35. An authenticable object comprising:
a base;
an elongatable recordable magnetic region carried by said base;
a square wave saturation recorded on a portion of said region; and
a unique machine readable authenticating representation, indicative of a
uniquely detectable characteristic of said magnetic region, as enhanced by
said square wave, carried by said base. |
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Claims |
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Description |
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FIELD OF THE INVENTION
The invention pertains to objects whose authenticity can be verified. More
particularly, the invention pertains to both documents and other types of
objects which carry a magnetic region. The magnetic region can be used to
verify the authenticity of the document or other object.
BACKGROUND OF THE INVENTION
Problems associated with the forging or counterfeiting of various types of
documents are longstanding and well known. For example, forgery of
negotiable instruments, currency or other documents of value is a
continuing and ongoing problem to issuers of such documents.
Historically, attempts have been made to protect such documents by using
special types of paper in combination with various printing techniques.
Techniques that have been developed include the use of papers which have
optically discernible characteristics such as water marks. Alternately,
the incorporation of planchets is well recognized in the creation of paper
to be used for negotiable instruments. More recently, papers have been
created that include detectable metal threads.
Printers have developed embossing techniques as well as techniques for the
creation of randomly varying optically discernible characteristics which
can be created during the printing process. Alternate printing techniques
have included the use of special inks as well as the use of highly complex
printed figures or graphics.
The verification and authentication problem extends to nondocumentary
objects of value as well. For example the verification and authentication
of paintings of substantial value can be a difficult, expensive and time
consuming process. Similarly, the authentication of other types of
nondocumentary objects which have value can also be an expensive and a
time consuming problem.
Another example of objects of value where there is a continuing and ongoing
authentication problem involves magnetic products such as computer disks
and video tapes. Large scale and widespread copying of both of these types
of objects results in substantial and ongoing losses to the producers of
the authentic objects.
The widespread use of plastic credit or debit cards has created yet another
set of authentication and verification problems. It is very common for
such cards to include pre-recorded magnetic stripes which include
transaction related information. This information can include account
numbers, credit limits, and/or personal identification codes.
However, such cards have been especially susceptible to forgery in view of
the fact that the magnetic encoding is almost always based on one or more
publicly known standards. One such standard ANSI x 4.16 - 1983 is utilized
in connection with many pre-recorded magnetic stripes associated with such
cards.
Another class of documents which suffers from similar types of forgery and
alteration problems includes transportation tickets . Airline tickets
represent a particularly difficult problem in that the value of a ticket
may vary over several orders of magnitude depending on the length of the
trip and the destination. However, the issuing agency may use the same
type of document for both inexpensive short trips as well as much more
expensive long trips.
Multi-use documents, such as rail transportation tickets, present yet
another type of authentication problem. Such documents are magnetically
alterable at the time of use to decrease the remaining value of the card.
However, if an original, unused document can be both physically and
magnetically duplicated to create a usable counterfeit document, the
issuing agency can lose substantial proceeds.
Various systems are known which can be utilized to create and authenticate
verifiable documents or credit cards. Some of the known systems are
optically based. Others are magnetically based.
One known type of system is disclosed in U.S. Pat. No. 4,423,415 issued to
Goldman. The system of the Goldman patent makes use of the fact that paper
documents have a randomly varying translucency characteristic. The
randomly varying translucency is a natural characteristic which results
from the process of manufacturing the paper.
In Goldman's system radiant energy, for example a beam of visible light, is
directed at a selected portion of a document. The amount of light which
passes through the document, as the document is being moved with respect
to the beam, can be sensed. The document thus becomes a light modulator.
Because of the nature of the process of making the paper medium, no two
documents will have the same variable translucency characteristic. As
such, the sensed light which passes through each document can be used as a
unique identifier of the document.
In accordance with Goldman's system, a representation of the sensed
variable translucency characteristic is recorded on the document prior to
use. When the document is placed into use, the variable random
translucency characteristic is again optically sensed. The sensed
characteristic is compared to the representation of the sensed
characteristic previously pre-recorded on the document.
In the case of an authentic document, the translucency characteristic
sensed at the time of use will correspond in a predetermined manner to the
translucency characteristic pre-recorded on the document at the time of
creation. A forged document on the other hand, based on a different piece
of paper, will not have a sensed characteristic that corresponds to the
pre-recorded representation unless the forger has a corresponding set of
equipment and knows the details of creation of the authentic document.
A variation of the above described Goldman system is disclosed in U.S. Pat.
No. 4,476,468. In this patent, also issued to Goldman, a light dispersing
coating is deposited on a surface of a card or other document. Reflected
light from the card is sensed and used to create a unique indicia for the
document. This indicia can be recorded on the card for later verification
purposes. The system of U.S. Pat. No. 4,476,468 can be used with opaque
documents since it depends on sensing a reflected light beam. On the other
hand, the system of the above-noted U.S. Pat. No. 4,423,415 requires a
document which is at least in part translucent.
Alternate optically based systems are illustrated in U.S. Pat. Nos.
4,034,211 and 4,094,462 issued to Host et al. and Moschner respectively.
The systems of the Host et al. and Moschner patents utilize a defraction
grating affixed to an optically accessible portion of the card or
document. Light reflected off of the defraction grating can be sensed and
used to form a randomly varying document characteristic. This document
characteristic can be encoded on the card for later verification purposes.
U.S. Pat. Nos. 4,114,032 and 4,218,674 both issued to Brosow et al.
disclose systems which use fibers of a magnetic or a magnetizeable
material. The surface of the document can be coated with such fibers or
the fibers can be added to the base material of the document when it is
being manufactured. In accordance with systems of the Brosow et al.
patents, the presence of the discrete magnetic fibers can be sensed over a
portion of the document. The number of sensed fibers can be used as a
document identifier. This number can be stored on the card for later
comparison during the verification process.
U.S. Pat. No. 4,303,949 issued to Peronnet discloses a magnetically based
verification system. The system of the Peronnet patent utilizes a magnetic
stripe with a thickness that varies in discrete increments along the
length of the stripe.
One way that is disclosed to form discrete thickness variations is to use a
two layer stripe. One of the layers is a continuously extending layer. The
other layer is a discontinuous layer applied above or below the
continuously extending layer. At the time of verification, a signal is
written to the multi-layer stripe. The resultant magnetization is then
sensed. The physically permanent multi-layer structure results in a
certain magnatization characteristic each time that the signal is applied
to the stripe. The resultant magnatization characteristic can then be
sensed in a read head. Then the stripe can be erased.
The Peronnet patent also discloses forming a stripe with discretely varying
thickness increments by removing discrete amounts of material from a very
thick stripe. This results in a stripe that has two or more regions with
substantially different thickness. For example, the Peronnet patent refers
to thickness increments greater than 40% of the base thickness.
U.S. Pat. No. 3,790,754 issued to Black et al. discloses a magnetic
verification system that utilizes two different types of magnetic
material. One type has a coercivity that is greater than the other type.
According to the system of the Black et al. patent, in a preferred mode,
two sets of magnetic ink are used to print intereaved bars having
different magnetic characteristics. The bars can be sensed to form a
digital number usable to identify the document.
While the known systems would appear to be effective with respect to
verification of certain types of objects, each has certain limitations.
The optically based systems require translucent or reflective surfaces.
Many objects, such as credit cards, are not translucent. Other types of
objects, such as disks or video tapes are not suitable for
self-verification via the use of reflected light systems. Further, many
types of products such as sports equipment or clothing do not have the
necessary physical characteristics to utilize the known systems.
Known magnetic systems result in increased manufacturing costs and
manufacturing complexity. In addition, special inclusions, modifications,
magnetic regions or layers distinct from the normal read-write magnetic
tracks are often needed.
Hence, there continues to be a need for an authentication/verification
system of more general applicability to a variety of objects. Such a
system preferably would be very inexpensive and would be integrally
includable in the object without requiring that the object have particular
physical characteristics.
SUMMARY OF THE INVENTION
In accordance with the invention, a method useable for verification of the
authenticity of an object is provided. The object has a continuously
extending, recordable, magnetic region positioned thereon. The magnetic
region includes a randomly varying magnetic characteristic unique to the
object.
The method includes the steps of detecting the randomly varying
characteristic of the magnetic region; retrieving a prestored
representation of that charateristic; and comparing the detected randomly
varying characteristic of the magnetic region to the retrieved and
prestored representation. The result of that comparision can also be
provided as one of the steps of the method.
In one form of practicing the method, the randomly varying characteristic
can be detected on a single layer region of the recordable magnetic
material which is allocated only for that purpose. Alternately, the
randomly varying magnetic characteristic can be detected in a portion of
the magnetic region on which transaction related or other information has
been recorded.
The prestored representation of the characteristic can be retrieved from a
selected location on the object. Alternately, the prestored representation
could be retrieved from a centralized data base.
An apparatus can be used for verifying the authenticity of an object which
carries a continuously extending recordable magnetic region. The apparatus
detects a randomly varying magnetic characteristic in the region which is
unique to the object. The apparatus includes a magnetic detector, such as
a read coil, which senses the randomly varying characteristic of the
recordable magnetic region.
A prestored representation of the characteristic can be carried on another
part of the object and can be detected by appropriate detection circuitry.
Alternately, the prestored representation of the characteristic can be
retrieved from a centralized data base. The apparatus can also include
comparison circuitry for comparing the detected randomly varying
characteristic to the retrieved, prestored representation of that
characteristic.
In accordance with the invention, a method of making a verifiable object
includes a step of providing a base portion. The base portion can be
flexible or rigid. In addition, the base portion can assume a variety of
shapes and can comprise a variety of types of documents.
A recordable region of magnetic material can be deposited so as to provide
a single layer. The magnetic material can be formed as an elongated
stripe. Alternately, the region of magnetic material could be formed in
any preselected shape.
A continuous, unique, permanent and randomly varying magnetic
characteristic of the region is then sensed. This sensed characteristic is
used to form a unique representation which can be readily encoded either
on the object or stored in a central data base. The representation can be
stored on the object in optically visible form which is machine readable,
such as in bar code form. Alternately, the representation can be recorded
onto a selected region of the magnetic material.
A system for making a verifiable object includes apparatus for applying a
recordable, single layer region of magnetic material on the object. The
region of magnetic material can be preformed as a section of a magnetic
tape. Alternately, the recordable region can be formed by applying a
coating in the form of an ink or the like to the object. The coating or
ink can carry the magnetic material in combination with a liquid medium or
vehicle. The vehicle can be evaporated or dried to provide a solid, single
layer region of magnetic material affixed to the object.
A continuous, unique, permanent and randomly varying magnetic
characteristic of the magentic material can be sensed by means of a read
coil. A unique encoded representation of the sensed characteristic can be
formed. This unique representation of the sensed characteristic can be
printed onto the object by means of a bar code printer. Alternately, the
unique representation could be recorded or written onto a section of the
recordable magnetic region by a recording head.
Further in accordance with the invention, a verifiable object can be
provided. The verifiable object includes a base region. The base region
can be flexible or rigid. The base region can be in the form of a
document. Alternately, the base region could be in the form of a
utilitarian object such as a computer disk or a video tape, or even an
object such as a tennis racket.
The object also includes a recordable region of magnetic material which is
positioned on the base portion. The recordable region can be deposited on
the base portion. In one form of the invention, the recordable region of
magnetic material can be deposited as a coating or ink which can then be
dried and hardened. Alternately, the region can be deposited by affixing a
preformed magnetic tape to the base portion. The region can be formed as a
single layer.
The recordable region of magnetic material includes a permanent, randomly
varying magnetic characteristic which is unique to the object. To enhance
the detectability of the randomly varying magnetic characteristic, a
selected electrical signal can be recorded onto the magnetic material.
The electrical signal can be a discontinuous signal. One usable type of
discontinuous signal is a digital signal. Alternately, the electrical
signal can be an analog signal. In one embodiment, the electrical signal
can be periodic.
In a preferred embodiment, the electrical signal can be recorded on the
magnetic medium so as to saturate spaced apart regions thereof. Saturation
recording will emphasize to a maximum extent the variations of the
magnetic medium.
The electrical signal can be recorded onto the magnetic region at less than
saturation levels. In this embodiment, less enhancement of the randomly
varying characteristic is achieved. Alternately, the varying magnetic
characteristic of an erased or non-recorded magnetic region can be
detected by moving the region past a read head. This sensed characteristic
is also unique to the magnetic region.
The enhancing signal can be a special signal recorded for that purpose.
Alternately, the enhancing signal can be a recorded sequence of
information. The recording location and form of the enhancing signal
determine the form of the detected randomly varying magnetic
characteristic.
In yet another form of the invention, a verifiable object can have a base
portion that supports the recordable region of magnetic material. A
representation, perhaps in digital form, of the non-uniform magnetic
characteristic unique to the object can be carried by the base portion,
displaced from that characteristic. This representation can by used later
in the varification phase by comparison with a new reading of the region.
Further, the magnetic region can be formed with first and second portions.
The first portion can be used for the purpose of encoding or recording
selected transaction related information. A second, nontransaction,
portion can also be provided. The second portion is displaced from the
first portion but may be immediately adjacent thereto. The second portion
extends for a selected distance and includes the permanent continuous
detectable randomly varying magnetic verification characteristic. A
selected electrical signal can be recorded thereon so as to enhance the
detectability of that characteristic.
In yet another form of the invention, a verifiable document can be
provided. The document can inc | | |
